Heat management prevents tissue buckling and collateral damage in NIR-laser tissue welding

摘要

In this study, a NIR erbium fiber laser tuned to a water vibrational overtone absorption band at 1455 nm was used to weld directly, in vitro, seventy-six porcine aorta tissues without the need for extrinsic solder materials. The tissues were divided into eleven groups based on the multiple and variable parameters that were used to weld the tissues. The effectiveness of the parameters used in each of the weld groups was evaluated directly at the time of the weld and also by tensile strength measurements done at the termination of the weld. Management of heat produced in tissues is of critical importance for good laser tissue welding (LTW). To address heat management issues, we report LTW using a transparent cover over the tissue specimen as a heat sink. Multiple scanning helps distribute the laser-generated heat and allows the tissue to cool between scans, reducing thermal damage. Better heat management using a transparent cover slide enhances the welding success. It reduces collateral damage and limits water evaporation and control the buckling of tissue around the line of apposition so that the two pieces that are welded do not move apart along the line of apposition due to buckling pressure and ensure a full-length weld.